100 ANNIVERSARY ADDRESS. 
ed, with exactness and truth in intelligible language. The same 
subtle fluid, by the same agency, bids fair to be an useful auxili- 
ary of the less mighty steam-engine—a mechanical power, and a 
means of propulsion ; and will, perhaps, in a short time, be econ- 
emized to dispel the darkness of night in our large cities. The 
telephone enables individuals to converse, each one from his own 
chamber, over widely intervening spaces; and ere long sound 
inay rival electricity in instantaneous communication. Except 
in imagination there is no power that thus mocks at distance. If 
we would find something analogous we must invade the realms 
of fiction. The authors of the Arabian Nights Entertainments 
‘do no more, who send princes and princesses through the air on 
enchanted horses, by the twist of a peg, thousands of miles in a 
moment—literally with the speed of thought; and our own im- 
mortal Shakspeare, perhaps dreaming of an ocean cable, evokes 
an adventurous sprite, able to “put a girdle round the earth in forty 
minutes.” These were the wildest vagaries of imagination, which 
have become in the nineteenth century sober realities. 
The imaginative standard of the past having thus been reduced 
toa fixed value, I may be permitted further to illustrate the 
practical necromancy of modern times. 
Daguerre, in 1839, after years of experiment, at length by a 
wonderful but simple process, transmitted the human portrait 
from life to plates of silvered copper, made sensitive to solar light 
by the vapour of iodine. Soon thereafter, the principle thus fully 
developed, improvements sprang up on every hand, and the re- 
sults so far are beautiful photographs, made permanent by auto- 
type, which give the most accurate delineations of works of art 
as well as natural objects. It is not to be supposed that they -will 
stop here, or that science has done with them. Genius will in time 
be able to fix the colours of the camera, as well as its shadows. 
Again, experiments on light, following a growing knowledge 
of the laws by which it is governed, have produced the speectro- 
scope, and now scientists assume, from careful analysis of the 
solar atmosphere, that they have a clue to ascertain the substance 
of the sun. 
In connection with this subject, the experiments of Mr. Lock- 
yer, a distinguished savant, and editor of Natuve, a journal well 
known in the world of science, with reference to the solar and 
stellar spectra, are of much interest. He has started an hypo- 
thesis, and justified it by experiment—that the elements them- 
selves, or at all events some. of them, are compound bodies, and 
that hydrogen is the principal elementary substance represented 
